Apparatus for changing a direction of floated articles on a floating conveyor



3,398,990 OATED 7, 1968 MIKIO MATSUMOTO APPARATUS FOR CHANGING ADIRECTION OF FL ARTICLES ON A FLOATING CONVEYOR Filed May 17, 1967INVENTOR. a, Viz

United States Patent "ice 3,398,990 APPARATUS FOR CHANGING A DIRECTIONOF FLOATEI) ARTICLES ON A FLOATING CONVEYOR Mikio Matsumoto, Ashiya-shi,Japan, assignor to The Tsuhakimoto Chain Mfg. Co., Ltd., and NipponSheet Glass Co., Ltd., both of Osaka, Japan Filed May 17, 1967, Ser. No.639,179 Claims priority, application Japan, June 16, 1966, 41/ 39,013 6Claims. (Cl. 302-29) ABSTRACT OF THE DISCLOSURE The disclosed apparatusfor changing the direction of floated articles on a floating conveyorhas a pair of shafts spaced from each other and disposed verticallyadjacent each other at a branching corner on a conveyor. Arms aremounted rotatably around said respective shafts and radially projecttherefrom. Other shafts are fitted at one end of said respective arms soas to move vertically and pads are mounted on the respective lowermostends of said other shafts for contacting said loads so as to be able tochange the direction of the load-s on the conveyor.

Background of the invention This invention relates to an apparatus forchanging the direction of floated articles on a floating conveyor, andmore particularly is directed to an apparatus for branching off fiatbottom surface articles from a main conveyor upon which they are beingcarried to a sub conveyor which is provided with a plurality of air jetholes therethrough so as to float the articles on the conveyor by meansof compressed air ejected through the holes.

Heretofore, floating conveyors in which a plurality of air jet holes areformed through a table so as to eject compressed air in order to floatloads :or flat bottom surface plates on the table and also so as to forman air-film layer on the surface of the table to carry the loads on thetable in any desired direction with an extremely small frictionalresistance have been utilized in very important situations intransferring flat plates such as glasses, plastics, etc.

In order to carry the flat bottom surface plates to their desiredlocation, the direction of movement of the plates must often be changedand in some cases it is preferable to do so while the plates are in amoving state. However, since the plates moving on the air table havetheir inertia in the direction of their initial motion, said inertiabeing directly proportional to the acceleration of the loads, it is verydiflicult and sometimes impossible to satisfactorily change thedirection of the moving plates due to the slip caused the loads whichmakes scratches on the surface thereof or due to the pressing forcesagainst the surface of the air table.

Summary of inventionv This invention eliminates the aforementioneddisadvantages in the case where it is desirable to change the directionof the floated loads or fiat bottom surface plates, and provides animproved apparatus for changing the direction of the moving platesfloated on the air table so that the speed of the plates in theiroriginal direction is gradually decreasing while their speed in the newdirection is gradually increasing.

It is an object of this invention to provide an apparatus for changing adirection of gas floated articles carried on a gas cushion conveyor inwhich the direction of said articles such as plate glasses or polishedmetal plates are easily and smoothly changed without any resultantscratches on the fiat bottom surfaces of the articles.

Patented Aug. 27, 1968 Another object of this invention is to provide anapparatus for changing a direction of moving articles on a conveyor inwhich the direction of the article is changed while moving at the sameperipheral speed as the original velocity.

A still further object of this invention is to provide an apparatus forchanging the direction of moving articles on a conveyor in which thepads for moving the articles thereon are able to be independentlyturnable on the arms.

Still another object of this invention is to provide an apparatus forchanging a direction of moving articles on a conveyor in which thedirection of movement of various types of articles can be changed simplyand easily.

A further object of this invention is to provide an apparatus forchanging a direction of moving articles on a conveyor in which thedirection of movement of the plates is automatically changed repeatedlyand easily.

These objects are achieved by providing a pair of shafts spaced fromeach other and disposed vertically adjacent each other at a branchingcorner on a conveyor. Arms are mounted rotatably around said respectiveshafts and radially project therefrom. Other shafts are fitted at oneend of said respective arms so as to move vertically and pads aremounted on the respective lowermost ends of said other shafts forcontacting said loads so as to be able to change the direction of theloads on the conveyor.

It is an advantage of this invention that the direction of the articleon the gas cushion conveyor can be changed without the application of arapid or strong increase or decrease in the force at the branchingportion by means of circular movement together with the floating actionon the conveyor so as to reduce the friction therebetween.

Yet another advantage of this invention is seen in the fact that eventhough the article of the conveyor fluctuates while its direction isbeing changed or if it has various thicknesses, the absorption of thepads makes adjustment for this.

Another important advantage of this invention is seen in the fact thatthe article on the conveyor is adapted to have its direction of movementchanged without any additional power consumption.

Furthermore, a still further advantage of this invention is seen in thatwhen the article has its direction of movement changed by an applicationof the pads thereto there is no slip or rotation between the article andthe pads due to the provision of the double bosses, inner and outer, onthe shaft for supporting the pads.

Still another advantage of this invention is seen in that the directionof the article on the conveyor is changed without any resultantscratches on the bottom surface of the article and in that thisoperation may be carried out easily and automatically.

Still another advantage of this invention is seen in that the article onthe conveyor is simply parallelogrammatically moved by means of thecurved arms between which the connecting rod is movably secured to botharms at the curved portion.

Other objects and advantages of this invention will further becomeapparent hereinafter, and from the drawings.

Brief description of the drawings FIGURE 1 is an explanatory plan viewshowing an apparatus for changing the direction of movement of a movingarticle on a conveyor in accordance with this invention;

FIGURE 2 is a diagrammatic plan view showing the apparatus for changingthe direction of movement of a moving article on a conveyor embodied bythis invention;

FIGURES 3 and 4 are partly sectional views taken on 3 lines a-a and b-b,respectively which appear in FIGURE 2;

FIGURE 5 is a side view of the apparatus shown in FIGURE 4.

Description of the preferred embodiment The principle of this inventionwhereby scratches or the like on the plates due to the inertia of theplate are avoided when the direction of the loads moving on the airtable are changed will now be explained. If the speed of the load in theoriginal direction on one air-film conveyor is V and if the speed towhich the direction of the motion of the load is to be changed isequivalent to the original speed, and if the mass of the plate isidentified by m, then the momentum of the load moving in the directionof the one conveyor is mv.

In order to change the direct-ion of the moving load on the one conveyorto the direction on the other conveyor which is angularly spaced fromthe one conveyor and moving at the same speed as the original conveyor,first the speed of the load on the one conveyor must be reduced to zeroin the direction of the motion of the one conveyor by applying to it acouuterforce, corresponding to a frictional force equivalent to themomentum mv, and then a force equivalent to the original momentum my hasto be applied to the plate in the direction of the other conveyor.

Inasmuch as a force is generally directly proportional to anacceleration in the same direction, a slip occurs between the load andthe surface of the conveyor, causing scratches on the surface of theload, if the direction of the moving plate is changed from one directionto another by first reducing the original acceleration and then byincreasing that in the new direction instantaneously and at the sametime.

Assume that the mass of the floated article or plate is identified by mand that the velocity of said plate, fioatedly carried on the aircushion conveyor, is identified by v, the momentum thereof is equal tothe product mv of the mass m and speed v. Assume further that the forcefor moving the plate is identified by p and that the time required forreducing the speed v to zero is identified by t, the force applied tothe plate is equivalent to the product pt 0f the force p and the time t.Therefore, it will be noted that the product mv is equal to pt, that ismv=pt. As will be clearly understood by those skilled in that art, itthe frictional force between the plate on the air conveyor and thesurface thereof is identified by f, the force f may be applied to theabove equation instead of the force 11, that is mv=ft, alternativelyf=mv/ t.

If the time t in the aforementioned equation ;f='mv/ t is decreased tozero, the force 1 is increased to infinity. Thus, when the plate movingon the conveyor is rapidly decelerated in order to change its directionof movement, the time t is caused to be decreased. As a result, theforce applied to the plate as a result of the deceleration is increasedthus causing scratches to occur on the bottom surface of the plate. Inother words, in order to change the direction of the moving plate on theconveyor, a great amount of force must be applied to the plate so thatthe original speed of the plate is first reduced to zero and then sothat the speed in the new direction is increased. Otherwise, slip willoccur between the bottom surface of the plate and the conveyor.

This invention utilizes a particular characteristic such that if theabove time t is increased, the force 1 will be decreased accordingly inthe equation f=mv/t. In order to actually reduce the force f when thedirection of the plate is changed, the direction of the plate moving onthe conveyor must be gradually changed toward the final direction. Thus,in this invention, the direction of the moving plate is changed so as tomove it peripherally at a predetermined angular velocity.

Suppose that the moving plate is contacted by any arm of length r, atits one end pivotally secured to the conveyor frame or the like at thebranching portion and at the other end pressing the plate so as to turnit gradually, and having an angular velocity identified by to, which ispredetermined so as to have the relation rw=v therebetween, and theplate has its direction changed from the X axis to the Y axis at a rightangle to the X axis. Further, the component velocity corresponding tothe X axis is identified by v and that corresponding to the Y axis isidentified by v The time from the beginning of the direction change isidentified by t. Then and, as is clearly understood by the aboveequations, the component speed along the original direction, that isalong the axis, is gradually decreased while the angular movement of theplate is advanced, at the same time that along the Y axis is graduallyincreased while the angle of the change in direction is increased. Thus,this invention prevents a rapid increase or decrease in the force beingapplied to the plate when its direction of motion is changed at abranching portion in the conveyor system.

In such a case, as will be clearly understood by those skilled in theart, a centrifugal force 0 to be applied to the plate in the horizontalplane is represented by the following equation, it the same referencecharacters are used:

According to one aspect of the present invention, there is provided anapparatus for changing a direction of gas floated articles carried on agas cushion conveyor having a pair of arms horizontally, pivotallysecured at a branching portion, which arms are adapted to turn inparallel, a pair of pads which are mounted to respective ends of thearms to be movable in elevation so as to press the article thereon,which pads are adapted to be turnable at the ends of the arms on a shaftpivotally secured thereto. Said shaft is supported by both inner andouter bosses thereby causing the pads to be independently turnable withrespect to the shaft, and the arm is adapted to turn at a peripheralspeed equivalent to the initial carrying speed on the conveyor, that isthe product of the radius of the arm and the angular velocity thereof.Thus, according to the present invention, the articles are alwayscarried at the same peripheral speed as the original velocity. The padsare adapted to substantially absorb the fluctuation of the article ordifferences in the thickness thereof.

According to another aspect of the present invention, there is providedan apparatus for changing a direction of gas floated articles carried ona gas cushion conveyor having curved arms which are adapted to behorizontally, pivotally secured at a branching portion and which armsare adapted to turn substantially in parallel. Pads which are adapted tobe mounted to respective ends of the arms so as to be movable inelevation are further adapted to be automatically controlled so as to belowered at the beginning of the direction change and to be raised at theend of said change. Means are provided for returning the arms to theiroriginal position after the completion of the direction change andconnecting rods are mounted at opposite ends on the respective arms,said rods having a length substantially equal to the distance betweenthe respective arms.

Although specific forms of the invention have been selected forillustration in the drawings, and the following description is drawn inspecific terms for the purpose of describing those forms of theinvention, this description is not intended to limit the scope of theinvention, which is defined in the claims.

Referring now to the drawings, and particularly to FIGURE 1, in theexplanatory plan view an apparatus for changing the direction ofmovement of articles such as flat plates ona conveyor is shown. The X-Xaxis is assumed to be laterally positioned in FIGURE 1, the YY axisbeing at a right angle to the X-X axis. The

article or flat plate is designated by reference numeral 1, which plateis originally moving on the XX conveyor at speed v. The pads aredesignated by reference character 2, the arms are identified by numeral3, and the shafts are designated by numeral 4. When the flat plate 1moving along the XX axis reaches the position identified by A in FIGURE1, a pair of pad-s 2 (the number of pads not being limited to a pair)move downwardly to the upper surface of the plate 1 so as to pressagainst it. Thereafter, the plate 1 is transferred so as to have itsdirection of movement changed by turning the arms 3 pivotally around theshaft 4 in the direction designated by Y-Y in such a manner that theperipheral speed of the pads 2 with the plate 1 is the same as theoriginal speed v. After the direction of movement of the plate 1 ischanged so that the plate 1 is positioned in position B, it is forced tocontinue moving at the same speed v.

As is explained heretofore, if the mass of the plate 1 is designated by'm the momentum of the plate 1 is determined by the product mv of themass m and the velocity v along the XX axis direction. In theconventional manner of changing the moving direction of the plate 4, thefrictional force f corresponding the momentum mv must at first beapplied against the moving plate 1 so as to stop it along the XX axis,then the force equivalent to the momentum mv must be applied to the newmoving direction along the YY axis so as to move said plate at the samevelocity as originally.

Since a force is generally directly proportional to an acceleration inthe same direction, if the direction of the moving plate 1 is changedfrom the XX axis direction to the YY axis direction by firstdecelerating then accelerating in the new direction simultaneously andinstantaneously, a slip occurs between the article or plate 4 and thesurface of the conveyor which causes scratches on the bottom surface ofthe plate. In order to avoid this, it is necessary to restrain this slipby applying a great amount of pressing force. However, in the case wherethe direction of a plate such as a glass plate or a plastic or polishedmetal plate is changed, such a slip or great pressing force will easilycreate such scratches on the bottom surface of the plates that it wouldbe impractical to use them.

In FIGURE 1, pads 2 are disposed so that they are in a position spacedfrom the center of the fulcrum or shaft 4 by the arms 3 which at one endare pivotally secured to the shaft 4 and at the other end are connectedto pads 2 and pressing the plate 1 so as to change the direction ofmovement of said plate in the space or radius r from the shaft to thepad, that is the length of the arm. The arm 3 is adapted to be turned atthe angular speed to so that the equation V=rw is satisfied. As isdiscussed hereinbefore, the following equations are considered:

v =v cos wt v =v sin wt when the plate 1 turns from the direction of theXX axis or zero degree to the direction of the YY axis or 90 degrees,that is, from time zero to time 1r/2w the component speed along theaxis, v decreases grad- =ually and that along axis v increases graduallyuntil it is accelerated to the original speed v.

Example Weight of the plate 100 kg.

Length of the arm 1.0 m.

Original speed 1) 18 m./min. or 0.3 m./see.

Acceleration due to gravity- 9.8 m./sec.

2 2 Centrifugal force a =1@ 100 0.09. -.O.92 kg.

From the above result, in this case, the centrifugal force is less than1 kg. Suppose that the coefiicieut of the friction of the contactingsurface between the pads and the surface of the conveyor is approx. 0.3,only 3 to 4 kg. or the like of the pressing force would be enough tocatch the plate 1 so as to move or turn it to change its movingdirection.

The structure of each part will now be explained hereinafter in FIGURE2. A gear 5 is positioned on one of the shafts 4 and is meshinglyengaged with a drive gear 6. Immediately before the flat plate 1 reachesposition A, the turning, driving device is initiated to turn said drivegear 6. The arrangement of vertical shaft 8 to which the pads 2 areattached is illustrated in FIGURES 3, 4 and 5. The vertical shaft 8 isjournalled in ball bearing 9 so as to be moveable up and down in anaxial direction. One leg of a lever 11, pivotal about shaft 12, isconnected to the vertical shaft 8 by means of a horizontal pin 10; theother leg of said lever 11 being connected to a piston rod 13 of an aircylinder 14. Thus, at the movement when the flat plate arrives in theposition A, the air cylinder 14 is activated to lower the pads 2 so thatthey press against the upper surface of the plate.

In the present case, the frictional force between the fiat plate floatedon the air layer of the table surface, and the table is extremely smalland that between the plate 1 and the pads 2 is sufficiently large,accordingly, the plate is firmly engaged by the apparatus and can berotated by the movement of arm 3. Thus, when the flat plate 1 has beenmoved to position B, the air cylinder 14 is de-activated, raising thepads 2 from the plate 1. The driving gear 6 is then reversed to returnthe arm 3 to the initial position, and thereafter the same operation isrepeated to change the direction of movement of the next flat plate 1.

The turning arm 3 shown in the drawings and connecting rod 15 alwaysform a parallelogram so that the respective two arms remain parallel toone another during turning. However, only one pad 2 and arm 3 need beused for turning a small fiat plate, or three or more may be used for alarger fiat plate.

Thus in accordance with this invention the inertia of the flat plate inthe first transferring direction may be transformed to turning energywhich together with an added external force is used to reduce graduallythe speed in the original direction in accordance with the cosine curvewhile at the same time, in accordance with the sine curve, graduallyincreasing the speed in the new direction. Accordingly, the direction ofthe flat plate may be changed easily and with a minimum powerconsumption. And further, it is easy to automatize the operation of theturning of the arm and the raising and lowering of the pads by usingelectric means such as a limit switch.

What is claimed is:

1. An apparatus for changing the direction of movement of gas floatedarticles carried on a gas cushion conveyor comprising a pair of armshorizontally, pivotally secured at one end at a branching portion of theconveyor, said two arms being adapted to turn substantially in parallel,a pair of pads being mounted on the respective other ends of said armsand movable in elevation so as to press an article on the conveyor, saidpads being rotatably mounted on said other ends of the arms.

2. An apparatus as set forth in claim 1, wherein driving means areprovided coupled to said arm at a peripheral speed equivalent to theinitial carrying speed on said conveyor, which speed is the product ofthe radius of said arm and the angular velocity thereof, whereby saidarticles are always carried at the same peripheral speed as the originalvelocity.

3. An apparatus as set forth in claim 1, wherein said shaft is supportedby inner and outer bosses, where-by said pad is independently turnableon said shaft.

4. An apparatus as set forth in claim 1 wherein said pads are movable onsaid arms toward and away from the surface of the conveyor tosubstantially absorb the fluc- 7 tuation of said article or ditferencesin the thickness thereof.

5. Apparatus for changing the direction of movement of gas floatedarticles carried on a gas cushion conveyor comprising a plurality ofcurved arms horizontally, pivotally secured at one end at a branchingportion of the conveyor, said respective arms being adapted to turnsubstantially in parallel, pads being mounted on the respective otherends of said arms and movable in elevation, connecting rods beingconnected between said arms, said rods being substantially equal inlength to the distance between the respective arms.

6. Apparatus as set forth in claim 5, wherein means are coupled to saidarms for automatically controlling said arm and pads so as to lower thepads at the beginning of a direction change and to raise them at the endthereof and to return said arms to their original position.

References Cited UNITED STATES PATENTS 2,527,394 10/1950 Brown et al.302-29 2,793,693 5/1957 Menk 193--36 X 3,138,408 6/1964 Bruce et al.302--29 3,194,376 7/1965 Holben 19336 3,198,499 8/1965 Stanley 302-29ANDRES H. NIELSEN, Primary Examiner.

